Kate Arnold Nutrition

September newsletter – The Colour of Food

September 15, 2010 4:17 pm

Here we are past mid summer with the hint of an approaching new season upon us – but we’re not there yet, and late summer to me still means vibrant foods full of colour and flavour! This months newsletter is all about colour and I’ve included a few more recipes than usual to get you all in the mood as a colourful meal is so much more appetising than a plate filled with pale “anaemic” food.

Eating a full spectrum of colours can not only help us receive a fuller range of nutrients in our diet but because all the senses contribute to the experience of eating, it helps our digestive process. Before we eat we look and smell, only then do we taste. Imagine if you will two plates of food: 1) grilled plaice, mashed potato and steamed cabbage, and 2) seared tuna steak with a red and green pepper ratatouille and sweet potato mash. Two very different plates of food, sending out totally different signals to our brain.

Food Colour

Colour and the appeal of various foods is closely related. Just the sight of food stimulates neurons in the hypothalamus. In trials, people presented with food to eat in the dark reported an important missing element for enjoying their meal: the actual sight of the food. For the sighted, the eyes are the first place that must be convinced before a food is even tried. This means that some food products fail in the marketplace not because of bad taste, texture or smell but because the consumer never got that far. Think how picky we have become with regard to the shape, colour and texture of our food and if any of you saw The Great British Waste Menu, on BBC1 a couple of weeks ago, what happens to so much of our food is that its just dumped because it does not fit into what we find acceptable.

The sight and smell of food is vital to our digestion. We need the salivary glands to start working and good digestion starts with the eyes and the taste buds. Bland food is traditionally the food for people who are recovering from illness. Whilst visiting someone is hospital recently, the bland food epidemic so common in institutions was at the forefront of my mind. White macaroni cheese on a white plate followed by white ice cream in a white container failed to get my taste buds going. Not an ounce of colour anywhere and hardly appealing to the eye.

There are three main classes of colour in foods: natural colours, browning colours, which are produced during cooking and processing, and additives. The principal natural colours, most of which, in refined form, are used as additives, are the green pigment chlorophyll, the carotenoids, which give yellow to red colours, and the flavonoids, with their principal subclass the anthocyanins, which give flowers and fruits their red to blue colours.
There has been much interest in carotenoids in recent years especially in beta carotene – besides being a natural orange pigment (in carrots, mango etc) it is converted in the body to vitamin A and has antioxidant powers and may be beneficial in reducing the risk of some cancers.

Food additives

Increasingly, food additive colours are based on anthocyanins derived from sources such as red grapes or beet but the first additive colours were the synthetic dyes. When synthetic dyes were discovered (mauve was the first, discovered in 1856 by the English chemist William Perkin) they were initially used in textiles, but by 1900 eighty chemical dyes were used in food in the USA. Chemical dyes have stronger colours than natural colouring agents such as cochineal. Many of these dyes were originally derived from coal-tar, and were commonly called ‘coal-tar dyes’. The term is still sometimes used although the dyes are no longer made from this source. Chemically, the dyes are azo dyes, that is they contain the azo group, which confers bright colours which vary in hue depending on the rest of the molecule.

In 1937 the dye butter yellow (dimethylazobenzene) was found to cause cancer in rats. The other azo dyes became suspects and one by one they have been weeded out of the list of acceptable additives. Today a limited range of azo dyes are still used. Several years ago, the makers of M&M’s which contain a variety of different coloured chocolate sweets, added blue to its pack. Apparently, the result of a vote by M&M fans. It does raise a few questions as of all the colours in the spectrum, blue is actually an appetite suppressant. Weight loss plans suggest putting your food on a blue plate. Or even better than that, put a blue light in your refrigerator and watch your munchies disappear!

Colour in foods can be seen mostly in fruit, vegetables, salad and herbs and as we are all meant to be eating five portions every day, we could be eating a rainbow of different colours on a daily basis. Colour is of course added to foods, and only as recently as ten years ago, buying a strawberry yoghurt still meant buying a pink yoghurt that had never really seen a strawberry but was full of colouring. We have come a long way now and most shoppers are savvy to the horrors of brightly coloured foods. I think its still pretty obvious if there is an artificial dye in a food, as it will look unnatural but still check the label. You can get wonderful natural colours like turmeric, saffron etc. Purified raspberries, blueberries or strawberries give terrific colours. Even peas made into soup have a fantastic natural colour. Colour is also so important in children’s diet as it is hard enough getting the five portions of fruit and vegetables into their daily diet. Colour (natural not added!) can really help-children as we know love bright colours.

Whilst on the subject of additives I thought you might find the list below useful.

Boil the potatoes for 12-15 mins until just tender. Meanwhile, flake the mackerel fillets into large pieces and cut the beetroot into bite-size chunks. Drain the potatoes and cool slightly. Mix the salad dressing and horseradish sauce together in a salad bowl and season. Tip in the potatoes – they should still be warm. Add the salad leaves, mackerel, beetroot, celery and walnuts, and toss gently.